Only my second post, but here are my 2 cents:
Under 200 yards a lever gun in 30-30 with modern ammo is just fine. My brother and I used to hunt with lever action marlins. His was a 30-30 with a 2-7x scope and mine was a .308 Marlin express with a 3-9x scope. We shot Hornady Leverevolution ammo and never felt under-gunned. The 30-30 with the Leverevolution ammo drops 12 inches at 300 yards. With traditional round-nosed loads I would keep my shots well under 200 yards. My brother killed an antelope around 300 yards with the 30-30 and Hornady ammo. (Might have been luck or stupidity). I killed a cow elk at ironically 308 yards with the .308 mx. The .308mx doesn't really belong in this discussion as it is closer to the .308 Winchester instead of a 30-30. Antelope are easy to kill so really all you have to decide is how far you want to be able to realistically shoot. Of the antelope I have shot all have been under 200 yards and many under 100 yards. I personally would think the joy of hunting with a lever-gun would be to put a peep-sight on the gun and try and hunt one under 100 yards for the challenge instead of trying to stretch the range. Years back writer Wayne van Zwoll did some articles about hunting with the 30-30 for a season with the Leverevolution ammo. He didn't feel under-gunned harvesting, pronghorn, deer, elk, and black bear with the 30-30. Have fun with the lever gun.